The UK deputy prime minister, Dominic Raab, and the transport secretary, Grant Shapps, have both thrown their weight behind the frontrunner, Rishi Sunak, in the race to succeed Boris Johnson as Conservative leader.
Raab, who had not previously backed a candidate, introduced Sunak as he formally launched his candidacy at an event in Westminster.
With the other candidates in a bidding war to promise tax cuts, Raab told the enthusiastic audience: “Just remember this: while others talk the talk, Rishi this month delivered the biggest tax cut for working people in a decade; and he did it because he’s a true Conservative, imbued with the values of enterprise, hard work and family. Rishi’s values are our values.”
He highlighted Sunak’s early support for Brexit, his “seminal” pamphlet on freeports, and his strong poll ratings relative to other candidates.
Also appearing on stage was Shapps, who has withdrawn from the Tory leadership race and backed Sunak, after it became clear he was unlikely to secure the support of the 20 MPs needed to progress to the ballot paper.
Key supporters including Oliver Dowden, who resigned as party chair after the disastrous Tiverton and Honiton and Wakefield byelections, the former chief whip Mark Harper, and the former trade secretary Liam Fox were also present.
Sunak has sought to distinguish himself from the rest of the field by declining to promise lavish tax cuts immediately, instead stressing the importance of not believing in “fairytales”.
In his own speech, he said it was time for a “grownup conversation” with the public about the challenges ahead. He said he wanted the campaign to be “a moment where the party and the country came together”.
Supporters brandished cardboard signs with slogans including “Restore trust” and “Reunite the country”.
Sunak also sought to explain why he had backed Johnson until last week, saying: “We owe it to the people who elected Boris in 2019 to explain why he is leaving office.
“Boris Johnson is one of the most remarkable people I’ve ever met, and whatever the commentators say, he has a good heart,” he said, insisting he would not take part in a “rewriting of history” about his premiership.
Sunak also denied rumours that Johnson’s former aide Dominic Cummings is secretly advising him. “Dominic Cummings has had absolutely nothing to do with this campaign and will have absolutely nothing to do with any government I have the privilege to lead,” he said.
Asked whether he would be dogged as prime minister by stories about his past tax affairs, following the recent controversy about his wife’s US green card, Sunak said: “They’re all out there and we’ve discussed them.”
Sunak’s wife, Akshata Murty, who is the daughter of the billionaire founder of the Indian tech giant Infosys, bowed to pressure to pay UK tax on her worldwide earnings earlier this year, after it emerged she was non-domiciled here for tax purposes.
The former chancellor has secured the highest number of public endorsements from MPs, who will narrow down the field rapidly to two candidates over the next 10 days. Sunak, who resigned last week, said he was bringing “a message of change”.
Sunak’s launch coincided with Tom Tugendhat’s launch speech, also introduced by his most high-profile cabinet backer, Anne-Marie Trevelyan. Tugendhat has the third highest number of backers – and stressed a commitment to growing the economy and underlined a commitment to deregulation as part of new “Brexit freedoms”.
Tugendhat stopped short of pledging new business tax cuts, saying they could not be “the only round in the magazine” but said he would slash fuel duty by 10p and reverse the national insurance rise. He said the UK would have “the most investment-friendly tax system in the OECD within five years”.
He said his leadership would rise to the challenges of the cost-of-living crisis in a way his cabinet rivals had not. “In a moment that is so desperate for so many – and when our service is most needed – we have retreated,” he said.
“We have retreated into division when we desperately need unity. When our nation needed our party to function, we retreated into faction. When the moment demanded service, we delivered scandal.”
He said the party had a duty to act because of the scale of the crisis being faced by millions of people. “Every day, families are seeing their savings being steadily eroded and wondering will this be over by Christmas? This just isn’t sustainable. It’s not fair. It’s not right. We must act.”
Asked if he was launching a leadership campaign only to secure a cabinet job, Tugendhat said his bid was “not a compromise position or a negotiating strategy”.
He said every candidate who made the final round should go to the Tory party membership: “No candidate should offer or accept compromise that goes behind the back of the membership.”
Kemi Badenoch’s campaign launch also took place on Tuesday, with the ousted former communities secretary, Michael Gove – her most high-profile backer – in the audience.
Badenoch said she had been a junior minister to both Sunak and Liz Truss, and that there should be a “genuine debate” about the next leader, and MPs “shouldn’t just assume that it’s a continuation of what we’ve had before but with different personalities”.
In an energetic speech in front of union jack flags that earned her a standing ovation from a packed room at the Policy Exchange thinktank, Badenoch criticised the “betrayal” of rivals’ tax cut pledges – which she said they would not keep.
She added she would not enter into a bidding war with MPs who claim “my tax cut is bigger than yours” but that she was committed to reducing taxes on businesses, families and individuals.